Mac OS X Server v10.5: Installing on a computer that won’t start up from the installation disc

Summary
If your computer came with a more recent version of Mac OS X than the version of the Mac OS X Server installation disc that you are trying to use, that disc may not be able to start up your computer. When you start the computer from the installation disc, the computer may display a blank or gray screen. In some instances, when installing Mac OS X Server over Mac OS X, the choice of Standard, Workgroup, or Advanced server configuration will not be offered.

Products Affected
Mac OS X Server 10.5
To install Mac OS X Server v10.5 on a computer that already has a later version of Mac OS X installed, follow these steps:

Be sure that you have completed the Mac OS X Setup Assistant on the target computer.
Run Software Update to install all available updates.
Connect your target computer to the secure Ethernet network where it will function as a server. If you have DNS service provided by your ISP, Internet router, or other servers on your network, make sure it is running and set up for your new server.
Launch Terminal and perform the following command:
$ sudo rm /var/db/.AppleInstallType.plist

Note: This utilizes the delete command with root privileges, so be sure to input the command correctly.

Insert the Mac OS X Server Install Disc.
Open the Install Mac OS X Server application.
Click the Install button. Note: If the button reads Restart instead of Install, then your computer can start from the installation disc. Simply click Restart and follow the onscreen instructions. You may skip the steps below.
Follow the onscreen instructions. The installer will install the necessary pieces of Mac OS X Server without removing any of the software already installed on your computer.
Once the software is successfully installed, close the Installer window and then immediately run Software Update. Install the latest Mac OS X Server update and any other recommended updates.
Software Update will prompt you to restart your computer when it is finished and the Server Assistant will appear. Complete it according to the instructions in your Mac OS X Server v10.5 Leopard – Getting Started guide.

Additional Information
If you choose the Advanced configuration option in Server Assistant in step 10, Kerberos may not start correctly after you finish setting up the server and restart. To correct this, run the following commands in a Terminal window, after setting up and restarting the server:

Important: After entering the first command you must type the password for the administrator account created in the Mac OS X Setup Assistant in step 1.

In addition, if you configure your server as a Kerberos Domain Controller (KDC) in step 10, and you encounter unexpected issues with client authentication, you may need to rebuild the KDC. For instructions, see this article.